JPS5912592A - Electronic range - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a microwave oven.

(B) Prior Art In recent microwave ovens, high-frequency heating is performed extremely easily based on operations on an operating section including a keyboard. Therefore, even if the door is open, if you mistakenly set cooking conditions such as cooking time on the operation panel and then operate the cooking start operation, high-frequency heating will occur and the high-frequency waves will leak to the outside. Extremely dangerous.

(C) Object of the Invention The object of the present invention is to prevent undesired high-frequency oscillation when the door is opened.

B) Structure of the Invention In order to achieve the above object, the microwave oven of the present invention has a heating chamber,
A door that opens and closes the opening of the heating chamber, a door detection means that detects the open state of the door, an operation section for setting cooking conditions such as cooking time, and a drive based on the cooking conditions set by the operation section. The cooking apparatus is characterized in that it includes a controlled high-frequency oscillation circuit, and when the door detection means detects a door open state, it prohibits the introduction of at least a signal based on a cooking start operation on the operation section.

Example) A microwave oven according to an example of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, (1) is a main body of a microwave oven, and an internal heating chamber is supplied with high frequency output from a magnetron to dielectrically heat an object to be heated. (
11) is an opening/closing door that closes the front opening of the heating chamber, (2) is a Koshidoro P panel as an operation unit provided on the front of the microwave body, (3) is a timer display device that digitally displays the cooking time, and (4) is a door that closes the front opening of the heating chamber. ) is a digitizer for the high frequency output level.
Output level/l' display device for displaying, (6), (6)
(7) is a keyboard consisting of 10 number switches from 0 to 9 used to set the cooking time and output level; (8) is a normally open type start switch for starting operation, and (9) is a power switch. , (101
is a plug outlet connected to a household AC power supply, α2)
is a door switch that turns off when the door (11) is opened or closed; θ4 is a digital logic circuit that will be described later; θ4 is a door latch as a door detection means that turns off when the door (11) is opened or closed. The switch <151 is a timer relay contact that is opened and closed by the output from the digital logic circuit (13), and the switch <151 is a timer relay contact that is opened and closed by the output from the digital logic circuit (13).
) and the bimetallic thermoswitch (19) for magnetron overheat prevention, and the main circuit power supply fin (19
) and -, (2υ and the wire are connected to the coil (23C) of the electromagnetic contactor which cuts the wire.
23) contact point, (261 is a lamp that illuminates the inside of the heating chamber,
(2) is an external pressure transformer to obtain the high voltage necessary to oscillate the magnetron, 9) is a resonant capacitor, (30) is a rectifier diode, 0], l is a capacitor that protects the diode. , Q is a heater transformer that supplies power to the heater (not shown) of the magnetron (28), Q is a noise prevention capacitor, and can is a coil that forms a noise filter with the capacitor (to);
(to) is an AC control element such as Tofiac that cuts off the current supplied to the high voltage transformer f2'i'+, and is a resistor connected to the gate of the AC control element; It is controlled by the output of the digital logic circuit 031 through an output control relay contact that connects to and turns on and off the signal to the gate of the AC control element (to). The fence is a resistor connected in parallel with the AC control element (2), and is connected to the lighting runde through the intermediate tap.

FIG. 3 shows a constant voltage power supply circuit for supplying a constant voltage to the digital logic circuit shown in FIG. 5, which will be described later. As explained below,
(2) is a step-down transformer that converts the household power source to a low voltage of about 12V to 24V, and is connected to the reed switch 4 from the electromagnetic switch (9) and the power supply fin circle. (c) is a rectifying diode bridge, yen is a smoothing capacitor, 0FjI is a transistor to keep the output voltage constant, and the transistor yen connected to its base amplifies the fluctuation value when the output voltage fluctuates. This is to return the voltage to the set voltage.

←η is a Zener diode for the reference voltage, the decoy is a variable resistor used to adjust the output voltage, (49) is a capacitor for smoothing the output side, (1501 (61) ld: %
FIG. 4 is a block diagram showing the basic circuit configuration of the present invention, which will be explained below. - is an encoder that converts decimal to binary, converting the signal from the keyboard (7) to 8-4-2
Convert to binary code according to -1 code. 2) is a timer circuit operated by the binary code from the encoder (58), which memorizes and counts the cooking time.It mainly consists of a down counter, and the contents of the counter are displayed on the timer display device (3) which displays the cooking time. is displayed, and when the displayed content reaches 0, the timer operation ends. (71) (721 (78) (74) is a display drive circuit that drives the timer display device (3) and includes a decoder that converts the binary code from the timer circuit (64) into decimal. (E) is an output level storage circuit for setting the output level μ, which is activated by a binary code from the encoder (68). The output from the encoder (group) to the timer circuit (64) and the output level storage circuit (-) is switched by the pretend 717221 circuit which is set or reset (7) when one is closed and stores its state. (@ is a control circuit that controls the entire digital logic circuit including the timer circuit (→), and the start switch (8) and door latch switch α are connected as inputs.
It is reset by the 110'' output from the zero detection terminal (E) of 7. In the generation circuit, this clock pulse is supplied to the timer circuit ((b). (101) is activated by the output of the timer circuit (u) to operate the timer relay θ6) and the timer relay contact 05) in Fig. 2. The timer control circuit that turns on, (@ is the coincidence detection circuit that detects the coincidence of the signals from the timer circuit ((b)) and the output level storage circuit ((b), and its output operates the output level control circuit (80-). Turn on the contact point - of the second cause output control relay (c). (85) is the output control relay (c).
A display drive circuit (135) that drives the l' display device is a notification device that uses a buzzer to notify you when the cooking time is about to end (for example, 3 seconds).

The general structure of the present invention has been explained above using the block diagram shown in FIG. Next, the detailed table structure will be explained based on the electric circuit diagram shown in FIG. Keyboards 0 to 9 (7) are keyboard switches used in electronic desktop calculators, etc., and display device f3 that displays cooking time and cooking level.
041 uses light emitting diodes, liquid crystals, fluorescent display tubes, etc., and uses a 7-segment system. Memorize cooking time
The timer circuit (54) that counts seconds, 10 seconds, minutes,
Presettable up/down counter (to) (6η(@(59)) that counts each digit of 10 minutes, gate circuit to convert 10 second digit counter (57) to hexadecimal number (circle, cooking time sequentially above 4) counter (size (5η(58)(
(B) The shift signal circuit (6) is a multi-pipe rake (@) that generates pulses of several tens of KH2. Vibrator (generated by @ and totals f(/<llys &f
A decoder (64) that converts the binary code of the counter (68) into a decimal number, a gate (66) that controls the oscillation of the multivibrator (@), and an inverter (111). .The decoder (6
4) Outputs 1, 3. Hundred and seven are counters (56) and (5) respectively.
? )(58)(59). The input terminal (@(68) (691 is the keyboard (7)
A signal indicating that is pressed, a signal indicating that cooking has not started, which will be described later, and a signal from the output terminal 9 of the decoder (64) are connected. The reset terminal R1R2 of the counter (n) receives a cooking time setting signal through the digit detection gate circuit (7o), a signal indicating whether 4 digits have been stored in the timer circuit (2), and a signal indicating that the keyboard (7) has been pressed. In addition, the other reset terminal RQ of the counter is connected to a flip-flop circuit FjII (output level setting switch of 9) that stores the cooking time and the states of the output level/V setting switches (5) and (6). (
6) Output terminal (107) that outputs ``1'' when pressed.
When this ゝゝ1'' output is input to the reset terminal (RQ), the counter is reset and the output level IL
/The output signal at the time of setting is not stored in the timer circuit (54). Output terminal Qa of the timer circuit (- counter (85) (57) (5B) (ω)
, Qb, Qc, and Qd are timer display devices (
3) is connected to the drive circuit (7S (A) (7B) (74)) and the output terminal (77) of the display drive circuit (71) (7B) (74) is Timer display device (3
) by well-known means. The output level storage circuit (55) is composed of a flip-flop (2) and a game (79) used to read a take into the flip-flop (90). Gate (a))
is the least significant digit (second) counter (detects when the output of the format reaches ``9''), and the gate (84) is the output level storage circuit (detects whether the - output is ``9'' or not). The gate circuit (88) is a circuit that delays the signal when the keyboard (7) is closed.
) is a circuit that generates a single pulse from the delayed signal. When the gate circuit (R) is turned on or the IB8 time setting switch (5) is closed, the memory contents of the timer circuit (- are erased (11), and its output (106) is sent to the counter (56). )(5η((E)(5
9) is connected to the reset terminal RD. Digital theory group 4 hi2r Control circuit WI (one output terminal (114) of 921) to control the entire f island ρ counter (
56) Gate (9@) for controlling the sending of Vc and output control relay (94)
) and timer relay (connected to the IQ drive gate (04), and the output terminal (110) of the other power is connected to the gate (66)
This prevents you from setting the cooking time while the machine is connected to the machine. The ll+ pulse generation circuit (96) includes a counter (four) and a waveform shaping circuit (bridged on the hakama).
60H2 or 5 supplied by electric forging fin (100)
A 1 Hz count pulse is generated by dividing the frequency of the 0H2(7) signal. This count bar/V-me is iIJki goo)
(98) is connected to the timer circuit (- least significant digit counter (56). The gate (4) drives the timer relay control circuit (101) during operation to operate the timer relay (+61). The output terminal (E) of the output level display drive circuit (85) is connected to the input terminal (102) of the gate (91), and when the output level setting is "0", the timer relay (1 clause) is not operated. Next, to explain the notification 1tLi ('l 3'5), the gate circuit (126) is connected to the timer circuit (
64) of the least significant digit of the counter (output terminals Qc, Q
The signal from d is ``0'', that is, the least significant digit of the counter (
It is detected that the content of (to) has become less than ゝゝ3''.

An inverter (127) inverts the output of the gate circuit (126). The gate circuit (i 28 ) is connected to the inverter (1
27) and the timer display 10 seconds digit, the display drive circuit (7) is connected to the output terminal (G) of the display drive circuit (10 seconds).
g) The terminal is set to V when all the memory contents of the minute, minute, and 10 second digit counters are 1% g//.
Outputs a "0" signal. In other words, the gate circuit (128) detects a signal in which the upper three digits become SS o" and a signal in which the least significant digit of the counter (-) becomes less than 1.3, and outputs the signal to the oscillation circuit f129. In other words, the υ oscillation circuit (129) starts oscillating 3 seconds before the timer ends.The oscillation circuit (129) is an unstable multivibrator circuit, and its control input (132) 1.(13)
3) performs oscillation and stopping. Input (132) becomes "1" for 3 seconds before the timer ends. Input (133)
is the control circuit (9″4 flip-flop circuit (
[3) becomes 1" during "during operation". Buzzer drive circuit (
130) amplifies the output (134) of the oscillation circuit (129) and drives the buzzer (131).

Next, the operation of the present invention will be explained in detail. Place the object to be heated in the heating chamber of the microwave oven fi+ shown in FIG. 1 and close the door (■). The door switch (lζ) is closed.

Then, when the power switch (9) is turned on, the digital logic circuit (131 is the output terminal (50) of the constant voltage circuit in Figure 3) (
A constant DC voltage is supplied through 61). At this time, the transistor (103) in the gate circuit remains "off" for a certain elapsed time due to the movement of the charging circuit of the resistor (105) and the capacitor (105).
When the charging of 05) is completed, it becomes ``on''. During this ``off'' state, the output terminal (106) of the gate circuit outputs an output of ``1'', and the timer circuit N is turned on by this ``11'' output. The counter of each digit (F4 (to)) (@ is reset, and the respective output terminals Qa to Qd output "0". Therefore, the timer display drive circuit (71) to (
74) does not operate, and the timer display device (3) does not display either. That is, as long as "0" is input to each input terminal (F) of each display drive circuit (from 70), the display drive circuit operates and remains strong, and furthermore, the output from the output terminal surface also decreases. It becomes ``0''. Therefore, if the upper digits are all ``'O'', the input terminals ABCD of the upper digits are
If the input is 0000, that digit will not be displayed on the timer display device.

For example, in the case of 00 minutes and 59 seconds, 00 minutes will not be displayed and 59
Only seconds are displayed. In this way, the counter (-1) is output from the output terminal (106) of the gate circuit.
~ (59) is reset, the timer display @ (3)
No numerical value is displayed. Control μ times lol! I (91 is the zero detection terminal (from the smell) of the display drive circuit (71) of the first digit, and is stopped (reset) by inputting "0". On the other hand, the 10 second digit counter (6η) of the timer circuit (54) needs to be converted into hexadecimal. For example, if you change from 15 minutes 00 seconds to 14 minutes 59 seconds, if you leave it as decimal, it will become 14 minutes 99 seconds. Therefore, you need to convert 10 seconds digit counter (5η to hexadecimal). In the present invention, this is performed in the hexadecimal setting gate circuit) and the Gumt circuit (60). That is,
The hexadecimal setting gate circuit (ff5J passes the signal from the decoder ((b)) when setting the cooking time and outputs the signal from the counter (6).
Reading is performed by sending a ``0'' signal to the LD terminal of η. While the timer circuit (54) is operating, the memory contents of the least significant digit (seconds) counter (56) and the 10 second digit counter (6η) are When the value reaches "0", a down-down signal is sent from the r terminal of the counter to the upper digit (minute digit) counter (5119).The down-down signal is sent to the hexadecimal setting gate circuit (in) After converting it into a narrow pulse of 9 width, its output terminal (115
) to the LD terminal of the counter (6η) and the gate circuit (6
It is designed to read "5" determined by the phrase,
For example, the time is stored as 15 minutes 00 seconds to 14 minutes 59 seconds.

Next, the output level setting method will be described. Output level/L
/ When the setting switch (6) is closed, the ゝゝIJL output is output from the output terminal (107) of the flip-flop circuit (fourth output terminal).Next, close the switch of one of the numbers 00 to 9 on the keyboard (7). Then, the input terminals A, B, C, and D of the output level storage circuit (i) are set to 2 by the encoder (5B).
A signal converted into an evolutionary code is transmitted.

At this time, the signal that the keyboard (7) has been closed via the gate (108) is delayed by the gate circuit (@) and converted into a single-shot Pμ by the gate circuit ((E).
The signal is transmitted to the gate (79), and the signal transmitted to the input terminals A, B, C, and D of the output level storage circuit (55) is read by that signal. At this time, reading is performed using a delayed single pulse, so even if the keyboard (7) chattering, there will be no erroneous reading. Then, the display drive circuit for output level/L/display operates,
The set value is displayed on the output level display device (4).

Next, when the cooking time setting switch (6) is closed, the output terminal (109) of the flip-flop circuit (91) becomes ``1''.
Give output. Then, when any switch on the keyboard (7) is closed again, the signal converted into a binary code by the encoder (58) is transmitted to the counter of the timer circuit (54).At this time, keyboard (7)
The signal indicating that is closed is also delayed by the gate circuit (-) and transmitted to (66). Further, the delayed signal is converted into a single pulse by the gate circuit (88), and the "1" signal is transmitted to the digit detection gate circuit (70).The digit detection gate circuit (70) is also a flip-flop circuit ( The υ gate is opened by the ``1'' output from the output terminal (109) of 91) and the AX 0'' output from the most significant digit display drive circuit (7(1)) and the counter (6B) is reset.

When the counter (68) is reset, the 9 terminal of the decoder becomes ``1'', and at this time the control circuit (
Since the @ output terminal (110) outputs a ``1'' output, the gate (66) is inverted and outputs a 0'' output. This "0" output causes the inverter (111) to invert and send the "1" output to the input terminal (62) of the multivibrator (62).
112). Then the multivibrator (62
) starts oscillating and supplies the pass/l' to the counter (6B).

A counter (68) counts the pulses and its output terminals Qa, Qb, Qc, Qd are binary coded.
/ St 2 "ゝゝ3"...ゞゝ9'' signals are supplied to the decoder ((b)) one after another. The decoder (k)
Convert the evolutionary code to a decimal number and output "XO" from each terminal. This "0" signal is sent to the counter (56) (571 (58) ([i9) When supplied to the input terminal (LD) of the counter, each counter starts operating and reads the contents of its inputs A, B, and C1D.Therefore, the signal sent to this input terminal (LD) is sequentially delayed starting from the upper digit. When the lower digits are supplied, the output of the lower digits is read into the upper digits and the digits can be shifted.''In this embodiment, the number of digits of the timer circuit (54) is set to 4 digits, that is, up to 99 minutes and 99 seconds. However, it is clear that the number of digits can be increased or decreased easily.When the "X9" terminal of the decoder (FA) becomes a "0" output, the gate (66) is inverted and the multivibrator ( 62) stops oscillating,
The read operation is aborted. When the keyboard (7) is closed again, the next reading is performed according to the above-mentioned order.

At this time, the oscillation frequency of the multi-vibrator system is set so that reading of four digits can be completed while the keyboard (7) is momentarily closed. In this way, when the memory contents of the 4th digit counter are read, the output terminal (E) of the 4th digit display drive circuit (74) is reversed from ``0'' to ``1''. .

This closes the digit detection gate circuit (?0), and even if you press the digit switch (7) from now on, the gate circuit (?0) is closed.
8) Single-shot bar/L/7. cannot pass, and the counter (68) cannot be reset.
In other words, it cannot be read. In this way, in this embodiment, once the 4-digit training time is set in the timer circuit (54), the setting is made such that no matter how much the keyboard (7) is closed, it will not be read. Preventing failure.

That is, the signal containing the fourth digit is taken out from the output terminal (E) for erasing unnecessary O of the display drive circuit (74), and the signal is used to open and close the gate of the digit detection gate circuit (70). The idea is to make it impossible to set more than 4 digits. In other words, when the memory content of the counter changes from zero to a number other than zero, the output from the output terminal (E) of the display drive circuit (74) becomes ゝゝ1/L, which closes the digit detection gate circuit (70). Input to the reset terminal of the counter (-) in the digit feed signal circuit (61) is prohibited, and therefore no further reading is possible.Since we used a signal to erase unnecessary ゝゝO'' in this way, the counter of the most significant digit There is no need to detect whether or not the memory contents of (mark) are "0", making the circuit configuration very simple.

After setting the cooking time and output level as described above, when the start switch (8) is closed, the flip-flop circuit (113) of the control circuit (92) is inverted, and the output terminal (114) is Also connect the output terminal (11
0) becomes ``0''. At this time, as the power stage is turned on, the time pulse generator circuit (96) continues to divide the power supply frequency, so the gate (4) is opened and Like 1
The clock pulses of the counter (+6) are supplied to the input terminal (CD) of the counter (+6), and the timer circuit (- starts counting.
)) is a subtraction counter, and each time a clock pulse is supplied, the stored contents are decremented by 1'', and eventually the timer circuit (the stored contents are opened when the set time elapses) The remaining time that has been decremented is memorized moment by moment.When the count progresses and the memory contents of the counter (56) in the least significant digit become zero, the output terminal (F) transfers the memory contents to the upper digit, that is, 10.
The bulk for the lower digits is supplied to the input terminal (Uπ) of the second digit counter ((to)), and the counter (56) has a memory content of 9" and a counter (6η) whose memory content is less than the set value. The value is decreased by ゝ1〃.The count further advances and when the contents of the seconds and 10 seconds digit counter (56) (5η) both reach ゝゝo'', the output terminal (F ) The digit bulk/V bus is supplied to the yoshikaranter (58). This digit down bulk is also supplied to the gate circuit (6), and a "0" output is output from its output terminal (115). , counter comparison) is supplied to the input terminal (LD) of
Its memory content changes from zero to the signals at its input terminals A, B, C, and D. At this time, during operation, the inverter (111)
Since output is ゝゝo〃, all the AND gates of the gate circuit (@ are closed, and the input terminals A, B, C, and D of the counter (ff) are connected to the output terminal Q of the counter (-).
$IC1010 instead of a, Qb, Qc, Qd signals
A signal of 5〃 is supplied, and ゝゝ5〃 is stored in the counter (57). In the end, the timer circuit (54) stores 59 seconds instead of 99 seconds after 00 seconds, for example from 15 minutes 00 seconds to 14 minutes 59 seconds, and the sexagesimal system of the clock is realized. Also, when setting the cooking time, the output of the inverter (111) is ``1'', so the output of the gate circuit (60) becomes the same signal as the output terminals Qa, Qb, Qc, and Qd of the counter (). +117) input terminals A and B.

It is transmitted to C and D. The count advances and the timer circuit (
When all the contents stored in the display drive circuit (54) become zero, the output terminal of the display drive circuit (7) of the least significant digit is inverted from "1" to "0", and the signal is sent to the control circuit (92).
The flip-flop (113) is inverted, and the output terminal (114) outputs an ``o'' output, and the other output terminal (110) outputs an N1'' output, and the operation ends. On the other hand, the control circuit (output terminal (1)
14) is 1'' and the output terminal (110) is 10'1, that is, during operation, the input (68) of the gate (66) is
) becomes 0, the gate (66) is closed and the cooking time cannot be set. Seventh, if the output level is set to something other than zero, the output level of the display drive circuit for displaying the output level is ``1'', so the gate opens. The timer relay θ6) is driven and its contact (15) is closed, so the blower motor θ7) and the electromagnetic contactor (23j) are driven and the microwave oven is operated.At this time, if the output level is set to zero, , the gate (95) is closed, so the timer relay α6) is not driven, the microwave oven is not operated, and only the timer circuit (64) is counted.Also, if the door (11) is opened during operation, High frequency oscillation is stopped.In other words, when the door is opened, the door latch switch θ and the door switch are opened, and the flip-flop (113) of the control circuit (9) is inverted and its output terminal (114 ) is 0",
The other output terminal (110) is ゝゝ11. '(9B) is closed, the supply of clock pulses is stopped, and the operation of the microwave oven is stopped. At this time, the timer circuit also stops counting, and the time remains memorized. Then, even if the door (!) is closed again, the flip-flop (113) remains as it is, the operation remains stopped, and the tire circuit ((b) is not counted. When the start switch (8) is closed, the operation resumes. .

Next, let's talk about how to control the output level. Let's assume that the output level is set to 5" using the keyboard (7).
The binary coded 0101 signal is transmitted to the output level /l/memory circuit F@ (55), and the output terminals Qa, Qb, Qc1Qd of the counter (91) output the 0101 signal as shown in Fig. 6 (c). appears and is input to the coincidence detection circuit (8o). 9 One timer circuit (lowest digit counter (
The output terminals Qa, Qb, Qc, and Qd of the
The output that changes momentarily as shown in (b) appears and is similarly input to the coincidence detection circuit (). And this - number configuration circuit 115''
In other words, when it becomes 0101, there is a match and the output terminal (1
17) is converted from ゝゝ1〃output to ゝゝ0〃output as shown in Figure 6) and the output level control circuit FI! The flip-flop (118) of I (81) is inverted from "1" to "XO" as shown in FIG. When the input is ``1'', the output (120) becomes ``0'', which is amplified by the transistors (121) and (122) to drive the output relay can and turn on the contact (b) to perform AC control. In is sent to the gate of the element branch and the AC control element (2
) to turn on the high voltage transformer reflex) power fin (11
6) and oscillates the magnetron. The least significant digit counter of the Kuimer circuit is a decrement counter, 9.8.7...2.1.0.9.8...
・The contents are now 9", which is 1001.
When the output terminal (123) of the gate (88) is inverted from "1" to "0" as shown in FIG.
is inverted from "0" to "1" as shown in FIG. Therefore, the input (124) of the gate (cA) is
The output relay (c) is deenergized and the AC control element (to) is turned off to stop the oscillation of the L magnetron.As described above, when a match is found in the match detection circuit ((b), When the output level is set to ``5'', the magnetron is turned on for 6 seconds when the output level is set to ``5''.
On-off control is performed at a cycle of 4 seconds. If the output level is set to ゝゝ7'', it will turn on for 8 seconds, and turn on for 2 seconds.
ff.

That is, by controlling the oscillation time of the magnetron,
9 8 2 The output can be adjusted in nine stages: 10, 1-6, 11...j. In this way, the magnetron (281) repeatedly oscillates and stops for cooking, and the timer circuit (6' counters) ~
When the content of (59) becomes zero, the display drive device of the least significant digit (
``0'' output is output from the zero detection terminal surface of 7, resets the control circuit (92), closes the gate (9B), and transfers the clock pass/V pass from the interstation pulse generator (96) to the timer circuit (54). In other words, when the contents of the display drive circuit (72) (7i19 (74)) of the most significant digit are zero, the A%B of the display drive device (7I) of the least significant digit is
, when the C1D input is OO (l O), that is, when the content of the counter G ~ of the least significant digit of the timer cycle @ ([4) becomes zero, the display driving device (7) π terminal '' output is input to the control circuit (92) and closes the gate (98) as described above. Therefore, the timer low path (64) stops the timer operation and the control circuit (92) is reset. As a result, the gate (95) similarly closes and the timer control circuit (101) stops operating, deenergizing the timer relay Qei and opening the timer contact θ~.At the same time, the dart (body 9 is closed and the output level control circuit ← The oscillation (by stopping the operation of the 8 odors and the magnetron effect) is also completely stopped.

On the other hand, the contents of the timer circuit (54) become zero for 3 seconds IIJ
In other words, 3 seconds before the end of cooking, the notification device (
135) operates and sounds the buzzer (131) until the end. Also, if the output voltage setting is ゝゝ9H, the output terminal (125) of the gate (&) becomes the output voltage ゝゝo'', so the output voltage will not be affected regardless of the condition of the coincidence detection circuit ((capital)). , rays are driven continuously and the magnetron (28) performs continuous oscillation.

Next, the door (11) opens and the door latch switch 0
If 4) is off, use the spring/1z (2) as the operating part.
Even if the start switch (8) is turned on, the signal based on the prayer signal is prohibited from being introduced into the subsequent flip-flop (113).6 That is, the start switch (8) is Gut (
92/, and does not open when the cutting gate (99 is the door latch switch θ4) is in the OFF state, so high-frequency cooking is not performed when the door (11) is opened.

In addition, in the present invention, the numerical output of the least significant digit counter ((e)) of the timer circuit (64) is used as an input to the coincidence detection circuit, but apart from the counter of the timer circuit, a dedicated input for the coincidence detection circuit is used. A counter may also be used.

Of course, in this case, an up counter may be used instead of a decrement counter. In addition, the heater transformer (to) is connected in parallel with the series circuit of the high voltage transformer y, (2r) and the AC control element (to) in order to conduct electricity even if the AC control element (to) is cut off. This prevents the symmagnetron (28) from being damaged by reversing the oscillation stop.

Furthermore, you can modify the timer settings while driving. That is, when the timer setting switch (5) is closed, the output (106) of the gate circuit (89) becomes ``1'', and the microwave oven stops because the memory contents of the timer circuit (threshold) are erased. All you have to do is set the lighting time and close the anzure start switch (8).

On the other hand, it becomes necessary to change the output level during operation. That is, when defrosting, etc., it is possible to make the pressure stronger at the beginning and weaker in the second half. Moreover, this change in output level can be done automatically without stopping the operation. In other words, when the output (107) of the flip-flop circuit (9) is in the state of ``1'', pressing the keyboard (7) will change the output level /l.
/Memory times It t55) memory contents are replaced. On the other hand, when the output (107) of the flip-flop circuit (91) is in the state of ``0'', press the output setting switch (6) to set the output (l 07 ) to ``1'', and then press the keyboard (7).
If you press , the memory contents of the output level memory circuit ((e)) will be replaced.

In addition, in the present invention, one keyboard is used for setting the output level and the output level, and the setting switch (6) [61] distributes the numerical value from the keyboard to the timer circuit (64) and the output level storage circuit (to). However, the setting switch (61f6+) may be omitted and a keyboard for the M science and output level may be used instead.

Furthermore, in this example, the timer circuit (the timer display device t3j) can be operated without operating the microwave oven to function as a timer device.In other words, when using another cooking device, one cooking mode can be used. In such cases, the timer circuit of the present invention (
54) can be used.

That is, after turning on the timer setting switch (5), store the predetermined interval in the timer circuit (■) using the keyboard (7), and then press the start switch (8).
In this case, only the timer circuit (54) operates and the counter 6)-
The time is displayed moment by moment on the display device (3).

(f) Effects of the Invention From the above explanation, according to ``91 Rakana ni Kibari'', a heating chamber, a door that opens and closes the opening of the heating chamber, a door detection means for detecting the open state of the door, and a striae. An operation section for setting cooking conditions such as time, l711 set on the operation section
a high-frequency oscillation circuit that is driven and controlled based on operating conditions, and when the door detection means detects a door open state,
At least the introduction of a signal based on the cooking start operation on the operation section is prohibited.High frequency waves do not leak to the outside, and it is extremely safe.

[Brief explanation of the drawing]

Fig. 1 is a front view of the main body of a microwave oven which is an apparatus of the present invention, Fig. 2 is an electric circuit diagram of the present invention, Fig. 3 is a constant voltage circuit that supplies the digital logic circuit of the present invention, and Fig. 4 is the same digital logic circuit. 5 is a detailed circuit diagram of FIG. 4, and FIG. 6 is a time chart of the present invention. (7)...Keyboard, (11)...Door, (8)
... Start switch, 041 ... Door latch switch, (58) ... Encoder, (54) - ... Timer circuit (, + (51 ... Output level storage circuit,
←0)...-number output circuit, (3)...timer display device, (4)...output level display device, (ff4)(
7'2) (78) (74) State...Display device drive circuit, (96)...Time parameter/l'me generation circuit, (135)
... Notification device, (70) ... Digit detection gate circuit. patent applicant

Claims (1)

[Claims] +1) A heating chamber, a door that opens and closes the opening of the heating chamber, a door detection means that detects the open state of the door, an operation section for setting cooking conditions such as cooking time, and cooking settings set using the operation section. A high-frequency oscillation circuit whose drive is controlled based on conditions is provided, and when the door detection means detects a door open state, at least the introduction of a signal based on a cooking start operation at the operation section is prohibited. A microwave oven featuring